Open
ECO4 Scheme
Up to £15,000
Fully funded insulation and heating upgrades for low-income and vulnerable households, delivered through your energy supplier at no cost to you.
Full grant detailsInsulation
Home Insulation in the UK — Costs, Grants and Types
Cavity wall insulation costs £400 to £1,000 for a typical UK home, while loft insulation runs £300 to £800. Both can be fully funded for eligible households through the ECO4 scheme. Solid wall insulation costs more at £8,000 to £22,000 but delivers the biggest energy savings for older properties. The Great British Insulation Scheme closed on 31 March 2026; the main routes to free insulation are now ECO4 and local authority programmes under the Warm Homes Plan.
ECO4 covers free upgradesWarm Homes Plan active0% VAT on installations
Last reviewed: April 2026By Eco Home Check Editorial Team
Costs at a glance
Insulation types and typical costs
Costs vary by property size and wall type. Eligible households may receive some or all of these measures free through ECO4.
Cavity wall insulation
£400–£1,000
Potential saving: Up to £180/yr
Suits homes built after 1920 with a cavity between inner and outer walls.
Loft insulation
£300–£800
Potential saving: Up to £150/yr
One of the most cost-effective upgrades available. Payback typically under 3 years.
Solid wall insulation (internal)
£8,000–£15,000
Potential saving: Up to £470/yr
For pre-1920 solid brick homes with no cavity. Reduces room size slightly.
Solid wall insulation (external)
£10,000–£22,000
Potential saving: Up to £470/yr
Applied to the outside of the building. Does not reduce interior space.
Available grants
Insulation grants in 2026
The routes to funded insulation for UK homeowners as of April 2026.
Active
Warm Homes Plan
Varies
The government's £13.2 billion programme for home energy efficiency. Local authority delivery routes include insulation as a core measure.
Full grant detailsCommon questions
Frequently asked questions
- What insulation grants are available in 2026?
- The main government insulation grants in 2026 are ECO4 (free upgrades for eligible low-income households) and the Warm Homes Plan (local authority delivery for a broader range of households). The Great British Insulation Scheme closed on 31 March 2026. Use our eligibility checker to see what you qualify for.
- How much does cavity wall insulation cost?
- Cavity wall insulation typically costs between £400 and £1,000 for a standard semi-detached home. The price depends on the size of the property and the number of cavities. If you qualify for ECO4 or a local authority scheme, you may receive this at no cost.
- Is loft insulation free under any current scheme?
- Yes. Loft insulation is one of the most common measures funded under the ECO4 scheme for eligible households. Your energy supplier coordinates the installation at no cost if your household meets the income or benefit criteria.
- What is an EPC rating and how does insulation affect it?
- An Energy Performance Certificate (EPC) rates your home from A (most efficient) to G (least efficient). Adding insulation is one of the most direct ways to improve your EPC rating, which can increase your property value and reduce energy bills. Many mortgage lenders now offer better rates for homes with higher EPC scores.
Check your eligibility for insulation grants
Answer a few quick questions about your home. Our checker cross-references ECO4, the Warm Homes Plan, and other active schemes to find what you qualify for.
100% freeTakes 2 minutesNo obligation